Which enzyme is commonly used to cut DNA at specific recognition sequences during genetic engineering?
Answer: A
Restriction endonucleases (restriction enzymes) recognize and cut DNA at specific palindromic sequences, making them essential tools in genetic engineering for creating recombinant DNA.
Q.2Easy
What is the primary purpose of using DNA ligase in genetic engineering?
Answer: B
DNA ligase catalyzes the formation of phosphodiester bonds between adjacent DNA fragments, sealing nicks in the DNA backbone after recombination.
Q.3Easy
Which of the following is an example of a vector used in genetic engineering?
Answer: A
Plasmids are circular DNA molecules found in bacteria that can be used as vectors to carry foreign DNA into host cells during genetic engineering.
Q.4Easy
What is the main advantage of using Bt cotton in India?
Answer: B
Bt cotton contains the Cry1Ac gene from Bacillus thuringiensis, which produces toxins lethal to cotton bollworm larvae, reducing pesticide use significantly.
Q.5Easy
Which Indian-approved genetically modified crop is widely cultivated for herbicide resistance?
Answer: D
HT Mustard (DHM-11) was approved for cultivation in India in 2022, engineered with herbicide tolerance for better weed management.
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Q.6Medium
The process of introducing foreign DNA into a plant cell using Agrobacterium tumefaciens is known as:
Answer: B
Agrobacterium tumefaciens naturally transfers T-DNA into plant cells, making it an efficient vector for plant genetic engineering. This process is called agro-transformation.
Q.7Medium
In CRISPR-Cas9 gene editing, what does the 'guide RNA' do?
Answer: B
The guide RNA is a synthetic RNA molecule that binds to the target DNA sequence and directs the Cas9 nuclease to cut at the correct location.
Q.8Medium
Which of the following statements about Golden Rice is correct?
Answer: B
Golden Rice is engineered to produce beta-carotene (pro-vitamin A), though its approval for cultivation in India was granted only in 2021. It aims to address Vitamin A deficiency.
Q.9Medium
What is the role of a 'selectable marker' gene in genetic engineering?
Answer: A
Selectable marker genes (like antibiotic resistance genes) allow researchers to identify and select cells that have successfully taken up the foreign DNA.
Q.10Medium
In the context of genetic engineering, what does 'homologous recombination' mean?
Answer: B
Homologous recombination involves the exchange of DNA segments between regions with similar sequences, allowing precise insertion of genes at specific locations.
Q.11Medium
Which technique would be most suitable for introducing multiple genes simultaneously into a plant cell?
Answer: B
Gene stacking or pyramiding involves incorporating multiple transgenes into a single organism, useful for combining multiple desired traits like herbicide resistance and pest resistance.
Q.12Medium
What is the major concern regarding the long-term cultivation of Bt cotton in India?
Answer: B
Continuous exposure to Bt toxin has led to the development of resistance in target insect populations in some regions, necessitating resistance management strategies and refugium planting.
Q.13Medium
Consider a genetic engineer wants to produce insulin using genetically modified bacteria. Which of the following is the correct sequence of steps?
Answer: C
The correct sequence is: (1) Insert the insulin gene into a vector, (2) Introduce the vector into bacteria (transformation), (3) Grow the bacteria in culture, (4) Extract and purify the expressed insulin protein.
Q.14Medium
Which of the following regulatory bodies in India is responsible for the approval of GM crops?
Answer: B
The GEAC (Genetic Engineering Appraisal Committee) is the apex body in India that approves the environmental release and commercialization of GM crops after rigorous evaluation.
Q.15Hard
A researcher used CRISPR-Cas9 to edit a disease-causing mutation in human embryo cells. What ethical concern is most relevant?
Answer: C
Germline (heritable) genetic modifications in humans raise significant ethical concerns about consent, unknown long-term effects, and societal implications, which is why many countries restrict human embryo editing.
Q.16Hard
A biotechnology company wants to develop a drought-resistant wheat variety using genetic engineering. Which genes would be most suitable to introduce?
Answer: B
Aquaporins regulate water transport while osmolyte biosynthetic genes help cells maintain turgor under water stress, both crucial for drought resistance in plants.
Q.17Hard
In the development of Bt Brinjal in India, which Bacillus thuringiensis gene was primarily used and for which pest resistance?
Answer: C
Bt Brinjal (approved for cultivation in 2023 in India) contains the Cry1Ac gene from Bacillus thuringiensis, providing resistance to the eggplant fruit and shoot borer (Leucinodes orbonalis).
Q.18Hard
What is the primary limitation of using bacterial plasmids as vectors for introducing large genes (>50 kb) into eukaryotic cells?
Answer: B
Plasmids typically have limited cloning capacity (usually 5-15 kb), making them unsuitable for large genes. BACs (Bacterial Artificial Chromosomes) or YACs (Yeast Artificial Chromosomes) are preferred for large inserts.
Q.19Hard
A genetically modified organism (GMO) shows unexpected phenotypic changes not related to the introduced transgene. What biological phenomenon best explains this?
Answer: C
When foreign DNA integrates into the genome, it can disrupt endogenous genes or be influenced by local chromatin context (position effect), causing unintended phenotypic changes beyond the transgene's direct effect.
Q.20Easy
Which enzyme is commonly used as a molecular scissors in CRISPR-Cas9 gene editing technology?
Answer: A
Cas9 is an endonuclease enzyme that cuts DNA at specific sites guided by RNA. DNA polymerase synthesizes DNA, reverse transcriptase converts RNA to DNA, and ligase seals DNA strands.
